In this Master’s Degree Thesis work I present the technological improvements of the Suspended Nanochannel Resonator (SNR) buoyant mass sensor technology developed in collaboration between the Manalis lab at the Koch Institute for Cancer Research – MIT and the CEA/Leti research center in Grenoble, France. 100nm thick piezoresistive gauges have been embedded in the hollow cantilevers of the SNR devices to allow a fully electrical piezoresistive readout mechanism of the beam’s resonance frequency. This achievement made it possible to design arrays of SNR sensors that are fluidically connected either in series or in parallel to perform different functions. Here, I compare the piezoresistive readout mechanism to the previously used optical lever scheme showing that they have equivalent performances: the optimized design of the piezoresistive gauge element has no negative impact on the SNR noise and a limit of detection in the attogram order of magnitude can be achieved.